Field of the Invention
The present invention relates to a turbine wheel comprising a turbine disk including a plurality of groove portions which are formed in its outer periphery; a plurality of turbine blades respectively including protrusions which are formed on their base ends, and fixed to the turbine disk by fitting the protrusions into the groove portions in an axial direction; and seal plates for sealing gaps between the groove portions and the protrusions by being fixed to respective one axial end surfaces of the turbine blades and the turbine disk.
Description of the Related Art
One such turbine wheel has been publicly known in Japanese Patent Application Laid-open No. 2005-163732. The seal plates of this turbine wheel are designed as follows. Each seal plate is formed from a curved elastic plate member that is fixed with a radially outer end portion of the elastic plate member in engagement with an outer annular groove which is formed in the one axial end surface of the turbine blade and opened inward in a radial direction, and with a radially inner end portion of the elastic plate member in engagement with an inner annular groove which is formed in the one axial end surface of the turbine disk and opened outward in the radial direction. Attachment of the seal plate is achieved by: elastically deforming the seal plate by pressing protrusions formed on the elastic plate member in a way that the seal plate comes into intimate contact with the one axial end surface of the turbine blade or the one axial end surface of the turbine disk; and with the seal plate thus kept elastically deformed, bringing the radially outer end portion of the seal plate into engagement with the outer annular groove of the turbine blade by moving the seal plate outward in the radial direction.
The above-mentioned conventional turbine wheel, however, involves the likelihood that: when the protrusions are pressed for the purpose of attaching the seal plate to the turbine blades and the turbine disk, the seal plate formed from the elastic plate member is excessively deformed and thus plastically deformed; and the seal plate resultantly loses its elasticity, and comes out of the outer annular grooves and the inner annular groove.